Recently, smart grid technologies are selected as a core business of next generation in many countries to be developed actively by many researchers. A smart grid system is aimed at decreasing power consumption. Technologies turning devices on or off are generally disclosed for the reduction of power consumption, as described in Korean publication No. 2012-0097551. However, the prior smart grid system does not provide an appropriate method for distributing energy in order to use energy efficiently.
Also, a blackout occurs frequently because many users consume the energy at a particular time. Therefore, it is needed a novel method for the reduction of energy consumption.